BioEnergy Research
·
2023
·
IF 3.6
Xie Wenlei,Wang Quan,Guo Lihong,Zhang Qiaofei
The efficient conversion of low-grade acidic oils to biodiesel is still a great challenge due primarily to the presented free fatty acids (FFAs) and moisture that significantly activate the used catalysts . In this premise, the acidic aluminosilicates (AAS) were employed as catalyst supports for loading of molybdenum and zirconium metals to synthesize the solid acid catalysts of molybdenum and zirconium doped aluminosilicates (ZrMo-AAS). The so-synthesized composite catalysts were characterized by various physicochemical techniques, and their catalytic activities were evaluated for the efficient biodiesel production by using acidic soybean oils as feedstocks. Results revealed that the targeted solid catalysts featured dual Bronsted-Lewis acidic sites and mesoporous structure with the acidity of 719 μmol/g and surface area of 459.7 m 2 /g, displaying high catalytic performances for the concurrent transesterification of triglycerides and esterification of FFAs with 92.3% of oil conversion and full FFA conversion to biodiesel at a reaction temperature of 130 °C for 12 h with a methanol/oil molar ratio of 30. This solid catalyst had good water and FFA-resistance capacity even with water content to 1% and FFA content of 40%, and moreover could be easily recovered by filtration with a steady reusability with a slight attenuation in the activity after five time reuses, rendering it to have the potential of cost-effective production of biodiesel from the low-grade oils.
研究领域:
化学工程
·
催化材料科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Dongxia Tian,Dongyang Liu,Kai He,Fu-Hua Sun,Xiaobing Hu,Shuhan Zheng,Xinyu Wang,Fei Liu,Hong Li
Flexoelectric effect possesses potential applications in electromechanical conversion, and the flexoelectric coefficient of ferroelectrics is greatly larger than that of ordinary dielectrics . Among the ferroelectrics, BaTiO 3 (BT) ceramics are lead-free materials, also receive a high flexoelectric response. However, it is still inferior to the piezoelectric response of lead-based piezoelectric materials . Herein, we inhomogeneously added x wt. % ZrO 2 into BT ceramics ( x wt. % ZrO 2 /BT ceramics, and x = 0.05, 0.5, 1, 2) to enhance the flexoelectric response of BaTiO 3 -based ceramics. The largest effective flexoelectric coefficients ( μ ρ ) of ∼800 μC/m at room temperature (RT) and ∼1500 μC/m near Curie temperature ( T C ∼ 127 °C) were obtained in 0.5 wt % ZrO 2 /BT ceramics, which is ∼6.7 times and ∼3.9 times larger than that of the as-prepared BT ceramics at RT and near T C (∼131.7 °C here) respectively. Although T C of the 0.5 wt % ZrO 2 /BT ceramics decreases compared with that of BT ceramics, its higher μ ρ than that of the as-prepared BT ceramics maintains a wide temperature range, extending to 160 °C. The enhancement of the μ ρ of the 0.5 wt % ZrO 2 /BT ceramics is largely attributed to the compositional heterogeneity between grain boundaries gathered with irregular paraelectric and orthorhombic Ba(Zr, Ti)O 3 , and grains which are tetragonal BaTiO 3 . The compositional heterogeneity is easily shaped into a strain gradient (namely a flexoelectric polarization), which plays a promoting effect on the flexoelectric coefficients.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Shiwei Song,Yanhui Wang,Xueqing Tian,Fanjia Sun,Yungang Yuan,Wei Li,Jianbing Zang
The synthesis of efficient and economical electrocatalysts for oxygen evolution reactions (OER) by the energy-saving approach has far-reaching significance for the production of hydrogen by water electrolysis. Herein, a facile route was proposed to prepare Zr-doped Ni/Fe (oxy)hydroxide layer grown on Ni-Fe foam (Zr-NiFe(OH) x /NFF) by chloride ions in-situ corrosion strategy in “NaCl-ZrOCl 2 ” mixed solution. The smooth NFF surface was effectively transformed into a rough multimetallic (oxy)hydroxide nanosheet with high electrochemical specific surface area and strong bonding to the substrate, resulting in excellent interface performance for mass transfer and charge transfer. Specifically, the incorporation of Zr 4+ regulated the electronic environment around the Ni/Fe center, as a result, adsorption energies were optimized and the inherent OER activity of active sites was enhanced. The Zr-NiFe(OH) x /NFF self-supporting electrode exhibited outstanding OER electrocatalytic activity where low overpotentials of 211 and 245 mV were obtained to achieve 10 and 100 mA cm −2 respectively, along with impressive durability for 40 h. This work provides a simple strategy for low-cost and mass production of the robust OER self-supporting electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zhuohao Qiu,Gaoyuan Chen,Xixi Bao,Jitao Xu,Chengyi Chu,Guangjian Peng,Jianjun Guo,Yuchuan Cheng,Aihua Sun
Barium titanate ceramics exhibit great potential in ceramic capacitors due to their excellent dielectric properties. However, with the highly integrated advancement in electronic components, the preparation of high-capacitance ceramic capacitors with complex structural design has been the focus in current research. In this study, the complex structural barium zirconium titanate is first prepared through direct ink writing (DIW) technique. Subsequently, based on the regulation of zirconium substitution on the phase transition temperature of barium titanate, we reasonably designed zirconium-substituted barium titanate ceramics with varying stoichiometric ratios to regulate the three-phase transition temperatures of zirconium titanate ceramics, and following optimized the sintering temperature of the over-substituted barium zirconium titanate, thus improving the dielectric properties of the barium titanate. The results demonstrate that the solid content of 65 % exhibited the optimal forming precision and the highest densification. Additionally, the over-substituted zirconia alter the phase structure of barium titanate, increasing the proportion of tetragonal phase and subsequently elevating the dielectric constant of the specimens. Notably, among all sintering temperatures tested, the specimen sintered at 1400 °C display the highest proportion of tetragonal zirconia-barium titanate and an optimal dielectric constant. This research offers valuable technical and theoretical insights for the preparation and utilization of zirconium-substituted barium titanate ceramics with intricate structures.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Yu Tang,Zhiyong Huang,Wei Wang,Yali Wen,Shuoxiao Zhang,Xi Chen,Zhibo Zhang,Zijia Yin,Tingting Yang,Tianyi Li,Leighanne C. Gallington,He Zhu,Si Lan,Steven Wang,Yang Ren,Zhenduo Wu,Qi Liu
The sluggish Li-ion kinetics restrict the rapid charging capabilities and contribute to the structural deterioration of Ni-rich cathode materials . Notably, crack propagation during repeated charging cycles deteriorates the electrochemical stability, which hinders the further development of high-energy-density batteries for electric vehicles (EVs). In this paper, we proposed a simple yet effective method to enhance the Li-ion diffusion and mechanical properties of Ni-rich cathodes via straightforward Zr doping. In-situ high-rate XRD reveals that the detrimental uneven delithiation under the fast-charging process has been largely alleviated. Particularly, a robust structure with higher modulus and fracture strength is constructed owing to the higher Zr-O bond. By mitigating the kinetic hindrance and increasing the particle’s stiffness, the proposed Ni-rich cathode shows an impressive 97.6 % capacity retention under a 5 C rate current. This work provides a facile and efficient strategy for large-scale production of fast-charging Ni-rich cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Haiqiang Lin,Hongyan Qu,Weikun Chen,Kang Xu,Jianwei Zheng,Xinping Duan,Hesheng Zhai,Youzhu Yuan
In gas-phase chemoselective hydrogenation of crotonaldehyde on Ag-based catalysts, zirconia doping on silica supports was found to improve catalytic performance in terms of unsaturated alcohol selectivity, hydrogenation activity, and stability. The surface modification of silica by zirconia doping favors the fine dispersion of Ag species due to the enhanced quantity and strength of surface acid sites, which enable construction of abundant catalytic sites effective for C O bond hydrogenation. High crotyl alcohol selectivity, exceeding 80%, and significant inhibition of monohydrogenation on the C C bond were observed on the optimal Ag/Zr–SiO 2 catalyst. Dynamic O 2 chemisorption measurement revealed that the pure Ag powders did not chemisorb O 2 irreversibly under 323 K, but SiO 2 or Zr–SiO 2 supported Ag catalysts did. The amounts of Ag active for O 2 chemisorption, which are at least one order of magnitude lower than that of surface Ag derived from TEM and XRD characterizations, match well with the perimeter interface Ag of hemispherical particles. A strong correlation between hydrogenation activity and O 2 uptake on those Ag/SiO 2 and Ag/Zr–SiO 2 catalysts with different Ag dispersions and deactivation degrees was observed, implying that the effective catalytic sites for crotonaldehyde chemoselective hydrogenation may originate from accessible interface sites with unique redox properties. Catalyst induction and deactivation were observed on both Ag/SiO 2 and Ag/Zr–SiO 2 catalysts in real catalytic operation. Changes in metal stable interface structure, rather than metal aggregation and coagulation, are assumed to be the main cause of irreversible catalyst deactivation, because the apparent Ag particle sizes changed slightly, but the oxygen chemisorption ability deteriorated considerably. Electropositive Ag sites interacting with neighboring oxygen from oxide supports at the ternary Ag–ZrO 2 –SiO 2 interface are proposed to account for highly selective C O bond hydrogenation to produce the desired unsaturated alcohol.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2017
·Vol. 7
·期 1
·41-49
·
IF 1.198
Peng Le,Zhang Kuibao,He Zongsheng,Yin Dan,Xue Jiali,Xu Chen,Zhang Haibin
In this research, Zr-doped Gd 2 Ti 2 O 7 pyrochlores, with the composition of Gd 2 (Ti 1- x Zr
x
) 2 O 7 , were firstly synthesized by self-propagating high-temperature synthesis plus quick pressing (SHS/QP) using CuO as the oxidant and Ti as the reductant. To improve the radiation resistance of titanate–pyrochlore, up to 35 at% Zr was incorporated to substitute the Ti site of Gd 2 Ti 2 O 7 pyrochlore (Gd 2 (Ti 0.75 Zr 0.35 ) 2 O 7 ). XRD and SEM microstructural characterizations showed the formation of a composite ceramic with the major pyrochlore phase and the minor Cu phase. The generated temperature of samples decreased from 1702 to 1011°C with increasing Zr content. The effects of sintering temperature and pressure time on phase composition and microstructure were systematically studied. Besides, the influence of thermal transmission on the whole combustion process was also explored. The pyrochlore-based waste form possessed high bulk density of 6.25 g/cm 3 and Vickers hardness of 10.81 GPa. The MCC-1 leaching test showed the normalized elemental leaching rates (42 d) of Cu, Gd, and Zr are 1.27×10 -2 , 1.33×10 -3 , and 8.44×10 -7 g·m -2 ·d -1 , respectively.
研究领域:
材料科学
·
核废料管理
✓ 已验证
产品关联
DOI
高影响因子
Micro & Nano Letters
·
2016
·Vol. 11
·期 2
·86-90
·
IF 0.723
Yiguang Li,Xueliang Liu,Xiaohong Li,Zhijun Zhang,Mengyun Zhao,Changming Su
Sulphated titania superacid (denoted as SO 4 2− /TiO 2 ) and sulphated zirconia-doped titania superacid (denoted as SO 4 2− /ZrO 2 /TiO 2 ) were prepared via a liquid-phase in-situ method. As-prepared SO 4 2− /TiO 2 and SO 4 2− /ZrO 2 /TiO 2 superacids were characterised by transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrometry. Moreover, the catalytic performance of SO 4 2− /TiO 2 and SO 4 2− /ZrO 2 /TiO 2 for the aquathermolysis reaction and viscosity reduction of the extra-heavy oil recovered at Shengli Oilfield (Dongying, China) was investigated. It was found that SO 4 2− /TiO 2 and SO 4 2− /ZrO 2 /TiO 2 as the catalysts for the aquathermolysis process of the tested extra-heavy oil have good catalytic performance. Saturated hydrocarbon, aromatic hydrocarbon, resin and asphalt composition of the tested heavy oil sample before and after aquathermolysis reaction indicates that the amount of the saturated hydrocarbon and aromatic hydrocarbon are increased, while the amount of resin and asphalt are decreased, showing promising potential in the industrial production of heavy crude oil.
研究领域:
化学工程
·
石油工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Xueying Gao,Xin Yu,Lincai Peng,Liang He,Junhua Zhang
A magnetically-recoverable multifunctional catalyst (Fe 3 O 4 /ZrO 2 @MCM-41) was tailored by the impregnation of ZrO 2 supported on mesoporous MCM-41 coated Fe 3 O 4 nanoparticles, which successfully served as a monolithic catalyst for the cascade conversion of furfural (FAL) giving high yield to γ-valerolactone (GVL), a versatile platform molecule. The ordered hexagonal framework of the parent MCM-41 well reserved after the embedding of Fe 3 O 4 and ZrO 2 . The incorporation of Fe 3 O 4 could not only impart the catalyst with a strong magnetism, but also tune its acidity to promote GVL production. An impressive yield of 85% was accomplished straight from FAL processing with iso -propanol as a hydrogen donor and solvent. The kinetic study demonstrated higher activation energy for levulinate-to-GVL step (86.9 kJ/mol) than FAL transfer hydrogenation (35.0 kJ/mol) and subsequent alcoholysis process (51.0 kJ/mol). The catalyst could be fully recovered by an external magnetic field and showed good reusability. The sustainability of this conversion represents greatly improved by the process intensification based on one-pot reaction, magnetically-recoverable multifunctional catalyst, and mild operating conditions without using gaseous hydrogen.
研究领域:
催化化学
·
纳米材料科学
·
可再生化学
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Jiaming Ye,Mingcheng Ye,Wenbin Ye,Zuyong Feng,Deping Xiong,Miao He
Lithium titanate (Li 4 Ti 5 O 12 /LTO) has been widely recognized for its superior stability and long cycle life as a negative electrode material for lithium-ion batteries. However, its limited specific capacity and poor rate performance have hindered broader applications. This study introduces an innovative approach to address these limitations by preparing Zr-doped Li 4 Ti 5 O 12 coated with reduced graphene oxide (rGO) (LTO-0.1Zr@rGO) using a wet chemical method combined with freeze-drying technology. The incorporation of Zr ions into the LTO lattice resulted in an increase in the lattice parameter and the unit cell volume. This increase facilitated the transmission of lithium ions and enhanced the material's conductivity. Furthermore, the rGO coating was found to significantly enhance the rate performance and cycle stability of the material. The LTO-0.1Zr@rGO composite demonstrated a high rate capacity ranging from 396.5 to 263.6 mAh g −1 at current densities varying from 0.2 to 5.0 A g −1 , with a stable capacity of 310.2 mAh g −1 maintained after 1000 cycles at a current density of 1.0 A g −1 . These results indicate the potential of LTO-0.1Zr@rGO as a promising anode material for high-rate and stable lithium-ion batteries.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Haoru Shan,Wenqiang Wang,Zhirong Wang,Junxiong Zhang,Jiayi Xia,Qixia Liu,Wei Zhang,Jianlong Ge,Qiuxia Fu
The development of continuous CoTiO 3 (CTO) fibers with prominent catalytic oxidation activity, tunable fibrous structures, and improved recyclability is appealing for application in efficient organic wastewater treatment; however, inescapable flaws remain, such as their inherent brittleness and adverse operability. Herein, a facile and effective strategy is proposed for the fabrication of flexible and mechanically robust CTO nanofibrous membranes through a combination of element doping and sol–gel-assisted electrospinning. Compared with pristine CTO fibers, the resulting zirconium-doped CoTiO 3 (ZCTO) nanofibrous membranes displayed remarkably enhanced flexibility and tensile mechanics, which were attributed to their lower crystallinity, smaller grain size, and fewer fiber surface defects. The developed ZCTO fibrous membrane demonstrated exceptional resistance to bending fatigue, retaining a polymer-like bending rigidity of approximately 25 mN even after undergoing 200 reciprocating bending cycles. Furthermore, the incorporation of zirconium into CTO clearly had an advantageous effect on the formation of oxygen vacancies, thereby enhancing the surface adsorption of peroxymonosulfate (PMS), accelerating the electron transfer process, and weakening the peroxy bonds. The tetracycline degradation efficiency of the ZCTO fibers remained at 81.4% within 10 min after 5 continuous cycles. Benefiting from their robust mechanical properties and excellent catalytic activity, the fabricated membranes demonstrated outstanding dynamic catalytic performance under gravity-driven conditions. More importantly, the reported strategy might be adopted and extended to develop a wide range of ceramic fibers with enhanced flexibility and mechanics for catalytic oxidation.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2024
·
IF 10.5
Xiao Gong,Yunhui Wu,Jiurong Li,Shiwei Zhang,Min Wu
As a new type of zero dimensional carbon based fluorescent nanomaterial , carbon dots (CDs) have been studied and developed for many years. Various methods have been explored to prepare multicolor CDs to achieve tunable fluorescence of CDs. However, synthesizing fluorescent CDs located in the long wavelength emission region remains a challenge. Here, through a simple one-step solvothermal method using anhydrous citric acid (CA) as the raw material, ZrCl 4 as both a metal element dopant and an inorganic salt matrix, and NH 3 ·H 2 O as nitrogen source, Zr-doped CDs (Zr-CDs) solution with long wavelength fluorescence emission and solid powders with blue fluorescence can be obtained simultaneously. By optimizing the usage of ZrCl 4 , the fluorescence emission of the prepared CDs red shifted from 596 nm to 650 nm. The introduction of Zr 4+ can cause a significant redshift. In addition, based on the sensitivity of CDs to oxygen, they can be used for the detection of trace amounts of H 2 O 2 . When using metal-organic framework (MOF) to encapsulate the Zr-CDs which is in the solution, optically stable CD@MOF powders can be obtained, which can be used for the construction of red light-emitting diodes (LEDs), demonstrating its potential application in the field of solid-state lighting. The synthesis technology is expected to provide favorable technical support for the future development of CDs.
研究领域:
材料科学
·
化学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）